Conventional playback devices, such as compact disk (CD) players and cassette tape machines, generally play a given recorded piece of music in substantially the same way every time, with fixed playback parameters such as tempo and playback duration. These and other playback devices are typically very limited in terms of user-specified playback parameters. For example, although conventional playback devices allow a user to select playback of a particular song, and to control output characteristics such as volume, base, treble and speaker balance, the devices generally do not allow the user to vary tempo, playback duration or other playback parameters for the selected song. Furthermore, although certain types of conventional CD players allow a user to select random playback of entire songs selected from one or more CDs, current CD technology does not permit sufficiently rapid switching of information to allow, for example, random selection of different user-specified portions of particular songs. Conventional playback devices are thus limited to playback of entire recorded songs with fixed tempo and playback duration.
Another significant problem with conventional playback devices is that the storage and playback mechanisms used in such devices are relatively delicate and prone to breakage. For example, both CD players and cassette tape machines include delicate drive mechanisms with moving parts such as motors, belts and wheels, which have a tendency to break down. This tendency is even more apparent in portable and mobile units. Although certain playback devices, such as the Sony Walkman.TM. and Discman.TM. products and automobile stereo systems, are specifically designed for playback in portable or mobile applications, the moving parts required in the CD or tape drives of these devices remain unduly susceptible to breakdown. Moreover, the delicate drive mechanisms often cause the playback audio output to skip or warble in reaction to road bumps, footsteps or other disturbances, resulting in an unpleasant listening experience for the user.
As is apparent from the above, there is a need for an improved playback device which can allow user selection of playback parameters such as tempo and playback duration, while substantially eliminating the frequent breakdowns, skipping and other problems typically associated with conventional devices.